Method of molding plastic part to container made of flexible web material, a device therefor, and container having plastic part molded thereto

ABSTRACT

A plastic part is molded onto a top of a container having folded flaps on the top of the container. The container is formed into a tube shape from a flexible web material with crease lines. Contents are filled into the tube of web material, the tube is transverse sealed and a primary shape container is obtained by cuffing the web material along crease lines. A final shape container is obtained with multi-folding of folded flaps onto the container top. A mold of an injection molding apparatus is applied against the top of the container, and fusion thermoplastic material is injected into the cavity formed between the mold and the top of the container. The thermoplastic material is then cooled, and the mold removed to leave the plastic part molded to the top of the container.

FIELD

[0001] A method is shown for applying a plastic part to a containerhaving flaps of a flexible web material by an injection moldingapparatus having molds and nozzles. The mold equipment and a containerobtained by the method or the equipment are also shown.

BACKGROUND ART

[0002] Plastic parts of an opening device such as a cover, a tap, and acap can be applied on a container or packaging.

[0003] A method of applying plastic parts includes forming a plasticpart by extrusion molding or injection molding using various molds(e.g., metal molds) in advance and, applying the plastic part withheat-sealing/adhesive on the packaging container. A method is also knownfor molding a plastic part directly to an opening top edge, simplecontainer side walls, and a top of a cup-shaped container including,e.g., flexible web materials. However, the use of this method islimited.

[0004] A container such as the octagonal-shaped container 1 of FIG. 3can be obtained by forming a tube from flexible web material, fillingthe tube with liquid food, transverse sealing of the tube material,cuffing, folding flaps to the container top and, forming the finalshape.

[0005] In manufacturing a folded container having folded flaps on thecontainer top, a primary container 51 is obtained by cuffing of sealedtube-like material along a crease line, as shown in FIG. 5(a). Finalcontainer 1, with an octagonal pillar shape, is obtained by triplefoldings, as shown in FIG. 5 (b), to container top 53 of folding flaps52, as shown in FIG. 5(c).

[0006] For example, in the container as shown in FIG. 7, the foldedflaps 52 are folded on the container top wall 53. There are gaps betweenthe folded flaps and the container top wall, gaps between the foldedflaps and the other folded flaps, steps between the container top walls,and steps between the folded flaps. The container does not have a simpledesign. When the plastic parts of a cover, etc., are applied to thecontainer top wall, the design of the plastic parts and the containermay be limited.

[0007] In a container having folded flaps, the flaps are folded by usingflexible web materials with crease lines, and folding along the creaselines. Further manufacturing processes, energy, material, and equipmentare necessary when using adhesive or heat sealing to fix the foldedflaps to the container top wall.

[0008] In a container having the flaps folded on the container top wall,dust, garbage, and small insects can stick in the gaps and stepsreferred to above when the container is being delivered.

SUMMARY

[0009] In various exemplary embodiments, a method is provided forapplying a plastic part to a container, an apparatus for applying theplastic part is provided, and a container formed using the method andthe apparatus is provided. According to the exemplary embodiments,simple designs are provided for the container or the plastic parts to beapplied to the container having folded flaps on the container top walland having gaps and steps on the container top wall.

[0010] According to exemplary embodiments, a method of applying aplastic part, the apparatus used in the method and a container resultingfrom the method are provided, in which, for fixing folded flaps onto thecontainer top wall, the further manufacturing steps, equipment, energyand material for applying adhesive or heat-sealing are not needed in thecontainer having folded flaps on the container top wall and having gapsand steps on the container top wall.

[0011] Exemplary embodiments provide a method of applying a plasticpart, the apparatus for applying the plastic part and the resultingcontainer, in which the gaps and steps of the container top can bedeleted and the containers will not be contaminated by dust, garbage,small insects, etc. that can become trapped in gaps or steps on thecontainer top wall during delivery.

[0012] A molding method according to an exemplary embodiment molds aplastic part onto a top of a container obtained by forming a flexibleweb material with crease lines into a tube shape, filling contents intothe tube, transverse-sealing and cuffing the tube web material, foldinga primary shape container obtained by the cuffing along crease lines,and forming a final shaped container with multi-folding of the foldedflap onto the container top.

[0013] The method includes forming a cavity between an inner wall of amold and the top of a container by applying a mold of an injectionmolding apparatus having a nozzle to the container top, injecting fusionthermoplastic material from the nozzle into the cavity, against theinner wall face of the mold and into gaps between the folded flaps andthe top face of the container, cooling the injected thermoplasticmaterial immediately, and leaving the plastic part formed to the top ofthe container by detaching the mold of the injection molding apparatusfrom the container top.

[0014] In an exemplary embodiment, the final shape of the containerformed using a molding method according to an exemplary embodiment issubstantially octagonal prism pillar shaped.

[0015] In an exemplary embodiment of the mold method, the container topis upturned and the mold of the injection molding equipment is appliedon the container top.

[0016] In another exemplary embodiment of the mold method, the containertop is down-turned and the mold of the injection molding equipment isapplied against the container top.

[0017] The cavity between the mold and the container top is sealed bypressure from the side walls of the contents-filled container during theapplication of the mold of the injection molding apparatus against thecontainer top.

[0018] In one exemplary embodiment of the method, the mold consists of asingle member.

[0019] In another exemplary embodiment of the method, the mold consistsof plural members.

[0020] A mold apparatus for applying a plastic part to a container madefrom flexible web materials includes a transporting means fortransporting a container to a position where the container top isbrought into contact with an injection mold. The container is formedfrom flexible web material with crease lines into a tube shape, thecontents are filled into the tube, the tube is transverse-sealed and thetube web material is cuffed. A primary shape container is obtained bythe cuffing along the crease lines. A final shape container is obtainedby multi-folding of folded flaps onto the container top.

[0021] The mold apparatus includes a nozzle for injecting fusionthermoplastic material. The mold forms a cavity by applying the mold tothe container top, and a passage connects the nozzle outlet with thecavity interior.

[0022] A cooling means is provided to cool the thermoplastic materialinjected into the cavity of the mold. A drive means moves the nozzle andthe mold to bring the mold against the container top, and to detach themold from the container top.

[0023] In an exemplary embodiment of the mold apparatus, an inner wallface of the mold is downwardly arranged, and the container istransported in an upward direction to bring the top of the containerinto contact with the mold.

[0024] In another exemplary embodiment of the mold apparatus, an innerwall face of the mold is upwardly arranged and the container istransported in a downward direction to bring the top of the containerinto contact with the mold.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIGS. 1(a)-1(c) illustrate a molding method according to anexemplary embodiment.

[0026] FIGS. 2(a)-2(c) illustrate sectional views of a container beingprocessed according to an exemplary embodiment.

[0027]FIG. 3 is a perspective view of an octagonal pillar container withfolded flaps.

[0028]FIG. 4 is a perspective schematic view of equipment for making acontainer with folded flaps used in an exemplary embodiment.

[0029] FIGS. 5(a)-5(c) illustrate perspective views of an octagonalpillar container with folded flaps.

[0030] FIGS. 6(a) and 6(b) illustrate partial perspective views of apackaging container according to an exemplary embodiment.

[0031]FIG. 7 is a plan view showing a top of an octagonal pillarcontainer with folded flaps used in an exemplary embodiment.

[0032] FIGS. 8(a)-8(c) are sectional views showing details of a methodaccording to an exemplary embodiment.

[0033]FIG. 9 illustrates a mold apparatus according to an exemplaryembodiment.

[0034] FIGS. 10(a)-10(c) are sectional views showing details of a methodaccording to an exemplary embodiment.

DETAILED DESCRIPTION

[0035] A container having a molded plastic part according to anexemplary embodiment is formed from a flexible web material with creaselines into a tube shape. Contents are filled into the tube, the tube istransverse-sealed, and the tube web material is cuffed. A primary shapecontainer is obtained by the cuffing along crease lines. A final shapecontainer is formed by multi-folding folded flaps onto the containertop.

[0036] A container cover of thermoplastic material is formed on the topof the container by injection of fusion thermoplastic material thatfills the gaps formed by the folded flaps on the top face of thecontainer.

[0037] The thermoplastic material is injected from a nozzle of aninjection molding apparatus, and the shape of the container cover formedfrom the thermoplastic material is determined by the inner wall of themold of the injection molding apparatus.

[0038] A schematic illustration of an apparatus used to form a containerfrom flexible web materials is shown in FIG. 4. The resulting containerwill receive a plastic part according to an exemplary embodiment.

[0039] A web of flexible packaging material having a thermoplasticmaterial layer as an innermost layer, and having crease lines on thesurface, is processed by the apparatus shown in FIG. 4. The flexiblepackaging material is transported from a roll of flexible packagingmaterial 41 by rollers. Strip tape 42 is joined to one end of thepackaging material web with a strip tape applicator. The packagingmaterial web then passes through a sterilization agent tank 43 and issterilized. The sterilization agent is removed with an air knife.

[0040] The packaging material web is formed into a tube by formingroller 44. The tube is longitudinally sealed by a longitudinal sealelement. Liquid food is filled into the resulting tube from a fillingpipe 45. While moving the tube down by a length equivalent to onecontainer, the tube is sandwiched by a seal jaw of a transverse heatseal apparatus and a facing jaw such that the tube is transverse-sealedin the transverse direction. A primary pillow-shaped container 46 isformed continually by this process. A transverse sealing zone of thecontainer is cut, and the individual packaging container 46 is separatedwith knives.

[0041] The flaps of the top and bottom of the separated pillow-shapedcontainer 46 are folded along the crease lines. A final shaped containeris formed by folding the folded flaps to the container top.

[0042] The layer structure of examples of the flexible web material thatcan be used in the containers according to an exemplary embodimentincludes a thermoplastic material layer as an outermost layer, a paperlayer, a metal layer of an oxygen barrier layer and a thermoplasticmaterial layer as an innermost layer.

[0043] Packaging material used in a container according to an exemplaryembodiment is not limited to the above example. Alternative packagingmaterials can be used. For example, the packaging laminate can includeone or more layers of a low-density polyethylene (LDPE), a printing inklayer, a fibrous substrate layer, aluminum foil, a paper substratelayer, and a layer of polyester (PET), in various combinations.

[0044] In addition, ethylene-alpha-olefin copolymer (so-calledmetallocene PE) polymerized by using a single site catalyst, can be usedfor an innermost layer and/or an outermost layer, as well as the aboveLDPE. Furthermore, as a practical substitute for a metal layer (aluminumfoil) of the oxygen barrier layer, a vapor deposit layer of inorganicoxide can be used. Furthermore, in addition to the above paper orfibrous substrate layer, a plastic substrate kneaded with powder orgranular in organics and plastic material can be used.

[0045] A mold method according to an exemplary embodiment is shown inFIG. 1. The container 1 is prepared by forming a flexible web materialwith crease lines into a tube shape, filling contents into the tube ofweb material, transverse sealing and cuffing the tube of web materialalong crease lines to form a primary shape container, and forming afinal shape container by multi-folding flaps onto the container top.

[0046] After forming the final shape container, a plastic part 4 ismolded to the top of the container.

[0047] A method according to one exemplary embodiment includes thefollowing steps:

[0048] (1) Applying a mold 2 of an injection molding apparatus having anozzle 3 onto the container top, thereby forming a cavity between aninner wall of the mold and the top of the container.

[0049] (2) Injecting a fusion thermoplastic material against the innerwall face of the mold and into the gaps between the folded flaps and thetop face of the container by injection of the fusion thermoplasticmaterial from the nozzle into the cavity.

[0050] (3) Cooling the injected thermoplastic material immediately.

[0051] (4) Detaching the mold of the injection molding apparatus fromthe container top to leave the plastic part molded to the top of thecontainer.

[0052] An example of a plastic part 4 molded onto the top of container 1is shown in FIG. 6. The shape of the final container is substantially aoctagonal prism pillar shape.

[0053] In the example shown in FIG. 6(a), an opening device 4 a of thecontainer covering the entire top of the container 1 is applied on thecontainer. The opening device 4 a includes a portion that can be raisedmanually, a portion that can be opened using a lever principle, and aportion supporting the other portions and covering the top of thecontainer.

[0054] In the exemplary embodiment shown in FIG. 6(b), a cap 4 of thecontainer 1 covering the entire top of the container 1 has been appliedto the container. In the cover 4, a hole 4 b for a straw is formed. Thehole is formed so that the remaining thickness of melted thermoplasticmaterial is thin, and a straw can be inserted in the hole during use.

[0055] In the embodiment shown in FIG. 1, the side of the container topturns upward, and the mold of the injection molding apparatus is appliedto the container top. FIG. 2 shows a section taken along line A-A ofFIG. 7, and illustrating the folded flaps 52 and the top wall 53 of thecontainer 1.

[0056] As shown in FIG. 2 (a), a cavity 5 is formed between the innerwall of the mold 2 and the top of container 1 by applying the mold 2 ofan injection molding apparatus having a nozzle 3 to the top of container1.

[0057] A fusion thermoplastic material is injected from the nozzle 3into cavity 5, against the inner wall surface of the mold and into thegaps between the folded flaps and the top surface of the container. Theinjected thermoplastic material is cooled immediately. The resultingplastic part remains formed to the top of the container when the mold 2of the injection molding apparatus is detached from the top of thecontainer 1.

[0058] The mold can include plural members 2 a, 2 b, as shown in FIG.2(b), or a single member 2, as shown in FIG. 2(a). The side mold members2 b in the exemplary embodiments of FIGS. 2(b) and 2(c) assist in anaccurate and secure application of the mold to the top wall of thecontainer during the molding operation.

[0059] The cavity 5 between the mold and the top of the container issealed by pressure (P) on the side walls of the contents-filledcontainer 1 when the mold 2 is applied to the container top. Thepressure P on the side walls of the container causes the top of thecontainer to expand outward against the mold members 2 b, therebyensuring a secure fit between the container top wall and the mold.

[0060] Another exemplary embodiment of a method for applying the mold 2of an injection molding apparatus to the container top, with the flapsof the container being folded against the top of the container 1, isshown in FIGS. 8(a)-8(c).

[0061] As shown in FIG. 8(a), the upward-directed inner walls of themold 2 of the injection molding apparatus receive the container top. Thecontainer top having the folded flaps 52 is applied into the cavity 5formed by the inner walls of the mold and the top of the container.

[0062] A supporting member 81 in mold 2 can assist in holding down thefolded flaps temporarily as the container 1 is lowered into the mold ofthe injection molding apparatus. The supporting member 81 can hold downthe folded flaps 52 temporarily during injection and/or after injectionof the fusion thermoplastic material, thereby controlling the amountthat the flaps protrude from the container top. The supporting member 81can also be used to form a straw-inserting hole 82 through the plasticpart 4 by acting as a core for the hole 82 during the molding operation.

[0063] The fusion thermoplastic material is injected from the nozzle ofthe injection molding apparatus into the cavity 5 formed between theinner wall face of the mold, the gaps between the folded flaps and thetop face of the container, as shown in FIG. 8(b).

[0064] The resulting plastic part 4 is formed to the top of thecontainer after the injected thermoplastic material is immediatelycooled and the mold 2 of the injection molding apparatus is detachedfrom the container top, as shown in FIG. 8(c). This arrangement canprevent or minimize the leaking of the fusion thermoplastic materialfrom the cavity 5.

[0065] Referring to FIG. 9, an exemplary embodiment of an apparatus formolding a plastic part to a container made from flexible web materialsis shown. The left half of FIG. 9 shows the condition when the mold 2 ofthe injection molding apparatus is raised away from the top of acontainer. The right half of FIG. 9 shows the condition when the mold 2of the injection molding apparatus has been lowered against thecontainer top, and a cavity 5 is formed between the mold and thecontainer top.

[0066] The apparatus includes a transportation means or movable platform91 that can transport the octagonal pillar shape container 1 havingfolded flaps on the top of the container into a mold position. A nozzle3 is provided for injecting fusion thermoplastic material into thecavity 5 formed between the mold 2 and the container top. A passage canbe formed in the mold for connecting the nozzle outlet with the cavityinterior. A cooling means can also be provided for cooling thethermoplastic material injected into the cavity of the mold. A drivemeans 92 can move the nozzle and the mold into position against thecontainer top.

[0067] The mold 2 can be moved vertically between the two positionsshown on the left and right sides of FIG. 9, and a mold support 93 canbe fixed to mold 2 through a toggle joint. The mold support 93 can bedriven by a hydraulic pressure type apparatus.

[0068] The container obtained using the above method and apparatus is acontainer having a molded plastic part applied to the top of thecontainer, with the container being an octagonal pillar shape container1 having folded flaps on the container top.

[0069] Referring to FIG. 10, exemplary embodiments of a method andapparatus for molding a plastic part to a container made from flexibleweb materials is shown. In the exemplary embodiment of FIG. 10, asupport spacer member 101 is arranged against the container top 53before forming a cavity between the inner wall of a mold and thecontainer top by applying the mold of an injection molding apparatushaving a nozzle to the container top. The support spacer member 101 canbe a compact, hollow foam body applied to the container wall of thecontainer top. In the illustrated exemplary embodiment, the supportspacer member is applied to the top of the container in advance. Thesupport spacer member allows for a reduction of the space in the cavity,and a reduction in the consumption of injection material. Furthermore,the mechanical strength of the plastic part can be reinforced.

[0070] As shown in FIG. 10(a) of the exemplary embodiment, the innerwall of the mold 2 of the injection molding apparatus having the nozzle3 is directed downward. The container top 53 having folded flaps 52 isapplied against the mold, and the cavity 5 is formed between the innerwall of the mold and the top of the container. The support spacer member101 is applied to the container top 53 in advance, as shown in FIG. 10(a).

[0071] The fusion thermoplastic material is injected from the nozzleinto the cavity 5, against the inner wall face of the mold and into thegaps between the folded flaps and the top face of the container, asshown in FIG. 10(b).

[0072] The injected thermoplastic material is cooled, and the mold 2 isdetached from the container top, leaving the plastic part 4 molded tothe top of the container, as shown in FIG. 10(c).

[0073] In the various exemplary embodiments, the material of the outerlayer of the flexible web material making up the container can be chosento be compatible material having good adhesive properties with theinjection-molded thermoplastic material.

[0074] The container having a molded plastic part according to exemplaryembodiments can be used to pack milk, juice, refined sake, shochu,mineral water, liquid food or other drinks.

1-14. (Canceled).
 15. A method of molding a plastic part onto a top of acontainer, the container formed from a flexible web material with creaselines into a tube shape, filled with contents, transverse-sealed andcuffed to form a primary shape container and formed into a final shapecontainer by multi-folding of folded flaps onto the container top, themethod comprising: forming a cavity between an inner wall of a mold ofan injection molding apparatus having a nozzle and the top of thecontainer by applying the mold of the injection molding apparatus to thecontainer top; injecting fusion thermoplastic material into the cavity,against the inner wall of the mold and into gaps between the foldedflaps and the container top by injection of the fusion thermoplasticmaterial from the nozzle into the cavity; cooling the injectedthermoplastic material; and detaching the mold of the injection moldingapparatus from the container top to leave the molded plastic part joinedto the container top.
 16. The method of claim 15, wherein: the shape ofthe container is substantially an octagonal prism pillar shape.
 17. Themethod of claim 15, wherein the container top is upturned and the moldof the injection molding equipment is applied on the container top. 18.The method of claim 15, wherein the container top is down-turned and themold of the injection molding equipment is applied against the containertop.
 19. The method of claim 15, wherein the cavity between the mold andthe container top is sealed by pressure from a side wall of thecontents-filled container and the application of the mold of theinjection molding apparatus against the container top.
 20. The method ofclaim 15, wherein the mold consists of a single member.
 21. The methodof claim 15, wherein the mold comprises plural members.
 22. A moldapparatus for molding a plastic part to a container comprising flexibleweb materials, the container being formed from the flexible webmaterials having crease lines into a tube shape, filled with contents,transverse sealed and cuffed along the crease lines, and having flapsfolded against a top of the container, the mold apparatus comprising: atransporting means for transporting the container into a positionagainst a portion of the mold apparatus; a nozzle through which fusionthermoplastic material is injected; the portion of the mold forming acavity when positioned against the container top, and having a passageconnecting an outlet of the nozzle with the cavity; a cooling means forcooling the thermoplastic material injected into the cavity of the mold;and a drive means for moving the portion of the mold and the nozzle intoa position against the container top and the mold and for detaching themold from the container top.
 23. The mold apparatus of claim 22, whereinan inner wall face of the mold is downwardly arranged and the apparatusis adapted to transport the top of the container upwardly against themold.
 24. The mold apparatus of claim 22, wherein an inner wall face ofthe mold is upwardly arranged and the apparatus is adapted to transportthe top of the container downwardly against the mold.
 25. A containerhaving a molded plastic part, comprising: a flexible web material withcrease lines, the flexible web material formed into a tube shape andfilled with contents, transverse sealed and cuffed along the creaselines, and formed into a final shape container with flaps folded onto atop of the container; and a container cover of thermoplastic materialformed by injection of fusion thermoplastic material from a nozzle of aninjection molding apparatus into a cavity having the shape of thecontainer cover and defined between an inner wall of the moldingapparatus and the top of the container and into gaps between the foldedflaps and the top of the container.
 26. The method of claim 15, whereina support member is temporarily arranged in the mold of the injectionmolding apparatus to hold the flaps.
 27. The method of claim 15, whereina support spacer member is arranged on the container top before formingthe cavity between the inner wall of the mold and the container top byapplying the mold to the container top.
 28. The method of claim 15,wherein the molded thermoplastic material is compatible with an outersurface material of the flexible web material.